using System;

namespace iTextSharp.text.pdf
{
    /// <summary>
    /// Implements the code 39 and code 39 extended. The default parameters are:
    ///
    /// x = 0.8f;
    /// n = 2;
    /// font = BaseFont.CreateFont("Helvetica", "winansi", false);
    /// size = 8;
    /// baseline = size;
    /// barHeight = size * 3;
    /// textint= Element.ALIGN_CENTER;
    /// generateChecksum = false;
    /// checksumText = false;
    /// startStopText = true;
    /// extended = false;
    ///
    /// @author Paulo Soares (psoares@consiste.pt)
    /// </summary>
    public class Barcode39 : Barcode
    {

        /// <summary>
        /// The index chars to  BARS .
        /// </summary>
        private const string Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%*";

        /// <summary>
        /// The character combinations to make the code 39 extended.
        /// </summary>
        private const string EXTENDED = "%U" +
            "$A$B$C$D$E$F$G$H$I$J$K$L$M$N$O$P$Q$R$S$T$U$V$W$X$Y$Z" +
            "%A%B%C%D%E  /A/B/C/D/E/F/G/H/I/J/K/L - ./O" +
            " 0 1 2 3 4 5 6 7 8 9/Z%F%G%H%I%J%V" +
            " A B C D E F G H I J K L M N O P Q R S T U V W X Y Z" +
            "%K%L%M%N%O%W" +
            "+A+B+C+D+E+F+G+H+I+J+K+L+M+N+O+P+Q+R+S+T+U+V+W+X+Y+Z" +
            "%P%Q%R%S%T";

        /// <summary>
        /// The bars to generate the code.
        /// </summary>
        private static readonly byte[][] _bars =
        {
            new byte[] {0,0,0,1,1,0,1,0,0},
            new byte[] {1,0,0,1,0,0,0,0,1},
            new byte[] {0,0,1,1,0,0,0,0,1},
            new byte[] {1,0,1,1,0,0,0,0,0},
            new byte[] {0,0,0,1,1,0,0,0,1},
            new byte[] {1,0,0,1,1,0,0,0,0},
            new byte[] {0,0,1,1,1,0,0,0,0},
            new byte[] {0,0,0,1,0,0,1,0,1},
            new byte[] {1,0,0,1,0,0,1,0,0},
            new byte[] {0,0,1,1,0,0,1,0,0},
            new byte[] {1,0,0,0,0,1,0,0,1},
            new byte[] {0,0,1,0,0,1,0,0,1},
            new byte[] {1,0,1,0,0,1,0,0,0},
            new byte[] {0,0,0,0,1,1,0,0,1},
            new byte[] {1,0,0,0,1,1,0,0,0},
            new byte[] {0,0,1,0,1,1,0,0,0},
            new byte[] {0,0,0,0,0,1,1,0,1},
            new byte[] {1,0,0,0,0,1,1,0,0},
            new byte[] {0,0,1,0,0,1,1,0,0},
            new byte[] {0,0,0,0,1,1,1,0,0},
            new byte[] {1,0,0,0,0,0,0,1,1},
            new byte[] {0,0,1,0,0,0,0,1,1},
            new byte[] {1,0,1,0,0,0,0,1,0},
            new byte[] {0,0,0,0,1,0,0,1,1},
            new byte[] {1,0,0,0,1,0,0,1,0},
            new byte[] {0,0,1,0,1,0,0,1,0},
            new byte[] {0,0,0,0,0,0,1,1,1},
            new byte[] {1,0,0,0,0,0,1,1,0},
            new byte[] {0,0,1,0,0,0,1,1,0},
            new byte[] {0,0,0,0,1,0,1,1,0},
            new byte[] {1,1,0,0,0,0,0,0,1},
            new byte[] {0,1,1,0,0,0,0,0,1},
            new byte[] {1,1,1,0,0,0,0,0,0},
            new byte[] {0,1,0,0,1,0,0,0,1},
            new byte[] {1,1,0,0,1,0,0,0,0},
            new byte[] {0,1,1,0,1,0,0,0,0},
            new byte[] {0,1,0,0,0,0,1,0,1},
            new byte[] {1,1,0,0,0,0,1,0,0},
            new byte[] {0,1,1,0,0,0,1,0,0},
            new byte[] {0,1,0,1,0,1,0,0,0},
            new byte[] {0,1,0,1,0,0,0,1,0},
            new byte[] {0,1,0,0,0,1,0,1,0},
            new byte[] {0,0,0,1,0,1,0,1,0},
            new byte[] {0,1,0,0,1,0,1,0,0}
        };
        /// <summary>
        /// Creates a new Barcode39.
        /// </summary>
        public Barcode39()
        {
            x = 0.8f;
            n = 2;
            font = BaseFont.CreateFont("Helvetica", "winansi", false);
            size = 8;
            baseline = size;
            barHeight = size * 3;
            textAlignment = Element.ALIGN_CENTER;
            generateChecksum = false;
            checksumText = false;
            startStopText = true;
            extended = false;
        }

        /// <summary>
        /// Gets the maximum area that the barcode and the text, if
        /// any, will occupy. The lower left corner is always (0, 0).
        /// </summary>
        /// <returns>the size the barcode occupies.</returns>
        public override Rectangle BarcodeSize
        {
            get
            {
                float fontX = 0;
                float fontY = 0;
                string fCode = code;
                if (extended)
                    fCode = GetCode39Ex(code);
                if (font != null)
                {
                    if (baseline > 0)
                        fontY = baseline - font.GetFontDescriptor(BaseFont.DESCENT, size);
                    else
                        fontY = -baseline + size;
                    string fullCode = code;
                    if (generateChecksum && checksumText)
                        fullCode += GetChecksum(fCode);
                    if (startStopText)
                        fullCode = "*" + fullCode + "*";
                    fontX = font.GetWidthPoint(altText != null ? altText : fullCode, size);
                }
                int len = fCode.Length + 2;
                if (generateChecksum)
                    ++len;
                float fullWidth = len * (6 * x + 3 * x * n) + (len - 1) * x;
                fullWidth = Math.Max(fullWidth, fontX);
                float fullHeight = barHeight + fontY;
                return new Rectangle(fullWidth, fullHeight);
            }
        }

        /// <summary>
        /// Creates the bars.
        /// stop characters
        /// </summary>
        /// <param name="text">the text to create the bars. This text does not include the start and</param>
        /// <returns>the bars</returns>
        public static byte[] GetBarsCode39(string text)
        {
            text = "*" + text + "*";
            byte[] bars = new byte[text.Length * 10 - 1];
            for (int k = 0; k < text.Length; ++k)
            {
                int idx = Chars.IndexOf(text[k].ToString(), StringComparison.Ordinal);
                if (idx < 0)
                    throw new ArgumentException($"The character \'{text[k]}\' is illegal in code 39.");
                Array.Copy(_bars[idx], 0, bars, k * 10, 9);
            }
            return bars;
        }

        /// <summary>
        /// Converts the extended text into a normal, escaped text,
        /// ready to generate bars.
        /// </summary>
        /// <param name="text">the extended text</param>
        /// <returns>the escaped text</returns>
        public static string GetCode39Ex(string text)
        {
            string ret = "";
            for (int k = 0; k < text.Length; ++k)
            {
                char c = text[k];
                if (c > 127)
                    throw new ArgumentException($"The character \'{c}\' is illegal in code 39 extended.");
                char c1 = EXTENDED[c * 2];
                char c2 = EXTENDED[c * 2 + 1];
                if (c1 != ' ')
                    ret += c1;
                ret += c2;
            }
            return ret;
        }

        public override System.Drawing.Image CreateDrawingImage(System.Drawing.Color foreground, System.Drawing.Color background)
        {
            string bCode = code;
            if (extended)
                bCode = GetCode39Ex(code);
            if (generateChecksum)
                bCode += GetChecksum(bCode);
            int len = bCode.Length + 2;
            int nn = (int)n;
            int fullWidth = len * (6 + 3 * nn) + (len - 1);
            int height = (int)barHeight;
            System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(fullWidth, height);
            byte[] bars = GetBarsCode39(bCode);
            for (int h = 0; h < height; ++h)
            {
                bool print = true;
                int ptr = 0;
                for (int k = 0; k < bars.Length; ++k)
                {
                    int w = (bars[k] == 0 ? 1 : nn);
                    System.Drawing.Color c = background;
                    if (print)
                        c = foreground;
                    print = !print;
                    for (int j = 0; j < w; ++j)
                        bmp.SetPixel(ptr++, h, c);
                }
            }
            return bmp;
        }

        /// <summary>
        /// Places the barcode in a  PdfContentByte . The
        /// barcode is always placed at coodinates (0, 0). Use the
        /// translation matrix to move it elsewhere.
        /// The bars and text are written in the following colors:
        ///
        ///
        ///    barColor
        ///    textColor
        ///   Result
        ///
        ///
        ///    null
        ///    null
        ///   bars and text painted with current fill color
        ///
        ///
        ///    barColor
        ///    null
        ///   bars and text painted with  barColor
        ///
        ///
        ///    null
        ///    textColor
        ///   bars painted with current color text painted with  textColor
        ///
        ///
        ///    barColor
        ///    textColor
        ///   bars painted with  barColor  text painted with  textColor
        ///
        ///
        /// </summary>
        /// <param name="cb">the  PdfContentByte  where the barcode will be placed</param>
        /// <param name="barColor">the color of the bars. It can be  null </param>
        /// <param name="textColor">the color of the text. It can be  null </param>
        /// <returns>the dimensions the barcode occupies</returns>
        public override Rectangle PlaceBarcode(PdfContentByte cb, BaseColor barColor, BaseColor textColor)
        {
            string fullCode = code;
            float fontX = 0;
            string bCode = code;
            if (extended)
                bCode = GetCode39Ex(code);
            if (font != null)
            {
                if (generateChecksum && checksumText)
                    fullCode += GetChecksum(bCode);
                if (startStopText)
                    fullCode = "*" + fullCode + "*";
                fontX = font.GetWidthPoint(fullCode = altText != null ? altText : fullCode, size);
            }
            if (generateChecksum)
                bCode += GetChecksum(bCode);
            int len = bCode.Length + 2;
            float fullWidth = len * (6 * x + 3 * x * n) + (len - 1) * x;
            float barStartX = 0;
            float textStartX = 0;
            switch (textAlignment)
            {
                case Element.ALIGN_LEFT:
                    break;
                case Element.ALIGN_RIGHT:
                    if (fontX > fullWidth)
                        barStartX = fontX - fullWidth;
                    else
                        textStartX = fullWidth - fontX;
                    break;
                default:
                    if (fontX > fullWidth)
                        barStartX = (fontX - fullWidth) / 2;
                    else
                        textStartX = (fullWidth - fontX) / 2;
                    break;
            }
            float barStartY = 0;
            float textStartY = 0;
            if (font != null)
            {
                if (baseline <= 0)
                    textStartY = barHeight - baseline;
                else
                {
                    textStartY = -font.GetFontDescriptor(BaseFont.DESCENT, size);
                    barStartY = textStartY + baseline;
                }
            }
            byte[] bars = GetBarsCode39(bCode);
            bool print = true;
            if (barColor != null)
                cb.SetColorFill(barColor);
            for (int k = 0; k < bars.Length; ++k)
            {
                float w = (bars[k] == 0 ? x : x * n);
                if (print)
                    cb.Rectangle(barStartX, barStartY, w - inkSpreading, barHeight);
                print = !print;
                barStartX += w;
            }
            cb.Fill();
            if (font != null)
            {
                if (textColor != null)
                    cb.SetColorFill(textColor);
                cb.BeginText();
                cb.SetFontAndSize(font, size);
                cb.SetTextMatrix(textStartX, textStartY);
                cb.ShowText(fullCode);
                cb.EndText();
            }
            return BarcodeSize;
        }

        /// <summary>
        /// Calculates the checksum.
        /// </summary>
        /// <param name="text">the text</param>
        /// <returns>the checksum</returns>
        internal static char GetChecksum(string text)
        {
            int chk = 0;
            for (int k = 0; k < text.Length; ++k)
            {
                int idx = Chars.IndexOf(text[k].ToString(), StringComparison.Ordinal);
                if (idx < 0)
                    throw new ArgumentException($"The character \'{text[k]}\' is illegal in code 39.");
                chk += idx;
            }
            return Chars[chk % 43];
        }
    }
}
